The overall goal of the present project is to investigate the neurophysiological substrate of the hedonic component of taste perception in humans, as a critical determinant of food selection. Sensible eating behavior is a key to good health and eating disorders often result in aggravated risks of disease and decrease in quality of life. A clearer understanding of the hedonic aspect of taste perception may suggest strategies to promote healthy eating patterns in the general population and in those with eating disorders. The present project will specifically address two questions. (1) Which cortical areas code the hedonic component of taste perception? (2) Does activation of these areas vary in different hedonic contexts? The project will take advantage of the power of the functional magnetic resonance imaging (fMRI) technique to image the brain with resolution sufficient to analyze the activation in individual subjects. The ability to take into account inter-individual differences is critical to the study of hedonic judgments, which are highly dependent on subjects' experience and culture. Emphasis will be placed on parallel psychophysical investigation of subjects in order to optimize the choice of stimuli and to correlate fMRI data with psychophysical parameters. The first question will be addressed by presenting pleasant and unpleasant taste stimuli to subjects in an fMRI scanner and by identifying cortical activation associated with stimulus pleasantness. The second question will be addressed by examining the cortical activity of the previously identified areas under different contextual conditions. Context will be manipulated through the visual presentation of appetizing or disgusting food pictures during stimulus tasting, as visual inputs represent a major source of sensory information possibly affecting cognitive states. A psychophysical investigation will aim at measuring the effect of visual information on hedonic evaluation of taste stimuli and the fMRI experiment will aim at identifying the cortical substrate of this effect; i.e. the areas with activity modulated by the hedonic changes related to the context modification. New knowledge about taste hedonics is critical to understanding food intake in order to facilitate development of strategies to promote healthy eating patterns.